celestion 66 needs Mid-range - Page 103 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 19th November 2013, 04:00 AM   #1021
reggie is offline reggie  Australia
diyAudio Member
 
Join Date: Feb 2010
Location: melbourne australia
Hi Alan (at al).
Well, after much procrastination (and several weeks down-time with a severe cold – my second in 2 months) I have my cross-overs finished. I plugged them into the system this morning and heard ….nothing. Been so long I’d forgotten how to turn my system on – 7 switches not 6. Anyway, it all sounded pretty good but something wasn’t quite right. Voices, which are usually centered between the speakers, seemed to be at the edges; a sign I think of incorrect polarity somewhere and sure enough I had reversed polarity on one of the MF500’s. So all good now. I’m so surprised that there are no hums, buzzes, whispy bits of smoke and/or burning rubber odours! Over the next few weeks I’ll try to voice them using combinations of the resistors you have recommended together with a variety of differing musical types. My resistor default settings at the moment are:
Midrange = 24.5uf capacitor/1.5 ohm R (alternatives 0.51 ohm or 1.0 ohm) and 4uf capacitor/3.9 ohm R (alternatives 2.7 ohm or 3.3 ohm).
Tweeter = 3.6uf and 11uf capacitors with the 0.51 ohm R/30.9 ohm R LPad (alternatives 0.75 ohm or 1.1 ohm and 24.9 ohm or 18.0 ohm or 62 ohm* (*to be used on its own!)
Alan, while convalescing I ordered replacement capacitors for the bass section of my new cross-overs (not wishing to pull the old ones apart). However, I was only able to get 70uf so I have supplemented these with a 4uf capacitor. So, the line-up there is now:
1 x 70 uf capacitor/1.5 ohm R plus 1 x 70 uf capacitor/1.0 ohm R with a 1 x 4uf capacitor/8.2 ohm R. But I think this last resistor was your suggestion if accompanying the existing 2 x 68uf Solens capacitors and the 1 x 8.2uf Solens I was going to take from the tweeter section of the old Xover. Could you advise me further on this please?
Lastly, thank you for your offer of assistance (Post #1014) to help me build some speaker stands. Unfortunately my wife thinks that 105cm’s is a fine (as in finite) height so, as an alternative, I have built little boxes for the cross-overs that hide under the console that holds all my gear.
Regards to all
Reggie
  Reply With Quote
Old 3rd December 2013, 03:05 PM   #1022
diyAudio Member
 
Join Date: Apr 2006
Location: Midlands
Default to Reggie above , + about placement of Inductors , + interim to DennyG

G'day Reggie ,

hah , you got your crossovers assembled sooner than I thought you would ,
and thus sooner than I had time to post about Layout and positions for the new large Inductors.

I did post a little in a previous post about positioning these large Inductors ,
but not all I had intended to ... at least not in any Post I have been able to find now , despite too long looking !

***

For all readers - placement of large Inductors for minimal Inductive Coupling:-

I previously advised a minimum of 10.5" x 10.5" board if all crossover has to be on one board.
{ Better is to use two boards:- 11" x 5" for the Woofer filter , and use the old Celestion board for the Midrange and Tweeter filters.}
Alternately use 11" x 10.5" or 10" if all on one board.

The new Woofer filter Inductors are so large they need to be a distance equal to or larger than the Diameter of the 3.5mH distant from each other ,
and larger distance away from all the other Inductors so that their Magnetic Fields do not excessively interact with each other.
Magnetic Field interactions are Inductive Coupling and will reduce the filter's effectiveness ,
because the coupling transfers part of the unwanted electrical signal into the next stage , or into another filter's stage , and thereby into the drivers.

To minimize this coupling:-

Put the new 3.5mH in one corner of the new board.
Put the large 2.2mH Woofer filter Inductor in the adjacent corner along the 11" side ,
{ or the 10.5" minimum side } ,
so both Woofer filter Inductors are on one side of the board.
Put the small 2.2mH Midrange filter Inductor in the corner diagonally opposite to the large 2.2mH Inductor.
Put the 0.14mH Tweeter filter inductor in the corner diagonally opposite to the 3.5mH inductor.
Thus the Tweeter filter's inductor is largest possible distance away from the primary source of bass coupling ,
hence very very little bass will get to the tweeter circuit where it would cause the worst audible effect.

Draw a line diagonally across the board from the 0.14mH inductor to the 3.5mH inductor.
Measure and mark the half-way point between the OUTSIDES of both those inductors along this line -
{ NOT the half-way point between the Centres of these two inductors }.
Stand the 0.34mH Inductor on its edge so it is like a Wheel ,
and place it on the line so that it could be rolled along from 0.14mH to 3.5mH and back.
Put some Silicone sealant on that half-way mark , position the 0.34mH on that in the direction I stated above ,
and tightly tie that inductor to the board with a Nylon cable tie.
Use Nylon , not Plastic , because plastic will stretch and loosen over time , but Nylon will stay tighter.
Do NOT use wire to tie the inductor , because wire being metal will become a Core to the inductor and thereby increase its Inductance.
In the position I have described the 0.34mH inductor will be off-centre away from the other diagonal of the board
from one to the other of the two 2.2mH inductors , and that is good for less Inductive Coupling from those.

Put the Woofer filter capacitors between the two Woofer filter inductors ,
and position them Parallel to each other , and so their axis's points from edge of board to the centre of board.
Put the 24uF Midrange inductor between the 3.5mH and the Midrange 2.2mH , and also axially pointed from edge of board to centre of board.
Put the 3.9uF Midrange cap between the 2.2mH midrange inductor and the 0.14mH , closer to the 2.2mH , and again pointing axially from edge of board to centre of board.
Put the two Tweeter filter capacitors one each side of the 0.14mH and near to it , and pointing axially from edge of board to centre of board.

Stick all those components to the board with Silicone sealant , and tie them tightly through the board with Nylon cable ties ,
but NOT the Resistors.
The resistors are small and light weight , thus do not need to be tied down.
They will dissipate their heat better and thus stay cool when held above the surface of the board.
Their wire end leads are strong enough to hold them above the surface ,
so solder their leads to the capacitors leads and then bend the resistors' leads gently and at a distance not less than half inch from their bodies so as to not stress the connections to their bodies.
Bend through no larger than 90 degree angle of the wire lead.
Make a part circle shape with the wire lead if you need to bend it further to hold the body above the surface of the board.
Basically , make the leads to be legs for the bodies of the resistors.


Reggie ,

if you have positioned some or all of your components differently , you can change some of them if you have used Silicone sealant ,
because it can be cut with a sharp blade.
The inductors need to be as I described , including the 0.34mH positioned like a wheel ,
otherwise you will have a degree of Coupling sufficient to reduce the effectiveness of these expensive components you have bought ,
and thereby a less audibly good crossover than is possible.
The capacitors' positioning is less critical , because there is a lot less Fields' coupling through those than through the inductors.
The bodies of the resistors should not be left touching any other component or surface.

The 70uF + 1 ohm Parallel with 4uF + 8.2 ohm is OK if you have this double pair in the circuit location you drew the capacitors/resistors pairs at in your Schematic in #946 on Page 95 ,
and the 70uF + 1.5 ohm in the other location in that circuit ... are they ?


As you have started with the least attenuation to the tweeter , leave that whilst you are deciding the midrange Series resistance.
If the tweeter sounds too bright , then decrease the 1.5 ohm in midrange to 1 ohm , and to 0.5 ohm if necessary , or even to no resistor there.
Leave the 3.9 ohm in the Midrange filter till you have decided all the others.
Basically , the amount of Series resistance in the Midrange and resistances in the L-Pad around the tweeter need to be chosen to achieve the balance you prefer with the woofer now at higher output.
You may have to increase the resistances in the tweeter L-Pad to achieve this.
After all the above is closest to your preference you can experiment with the resistance to the 4uF in the midrange filter.
This resistor not only changes the upper-midrange/lower treble level , but also changes the Vertical listening axis.
It changes the Vertical axis because it changes the Phase response of the midrange filter.
This is evident in the series of simulated response plots that DennyG has posted recently.
If you are not happy with the integration between mid-dome and tweeter at the listening height you are now restricted to with no loudspeaker stands ,
then decrease from 3.9 ohm to 3.3 ohm , and even to 2.7 ohm if necessary.
If none cause the effect you want , then report here which is closest , or between which two resistances is closest ,
or whether neither the 3.9 or 2.7 is far enough outside the range of 3.9 <--> 3.3 <--> 2.7 .

***

Reggie ,

you seem to have a lot of money to spend , as you bought new caps for the Woofer filter !
Please post here the Brand name and Seller of these 70uF capacitors ,
which I hope are not Electrolytics ... ?
so that other readers can buy those if those are the easiest for them to obtain.

*** *** ***

G'day DennyG ,

there is a lot in your series of plots that requires comment by me to put all into useful perspective.
I will get to that when I have time available.
I attended to Reggie's new crossover first , because he is fine-tuning it now.

To be even more useful it would be good to have similar simulated plots for the HF2000 tweeters ,
but that will be more difficult to do as result of their much larger change of Impedance through the crossover region.

We can do a series for the Woofers to see if any significant differences between using two 72uF versus 68uF + 75uF { or close to 75 as yours is }.
This series could include changes to the resistors ,
but there is a lot more compromise there with the resistors between minimal for filtering of upper midrange versus more for reducing resonances
than is in the midrange filter's options.

Doing a series of simulations for the low-midrange end of the midrange filter will not show much of use unless many plots done ,
including specifically for different frequencies with different Impedances , because of the very large change of Impedance there ,
and it will all be quite complicated to explain.
I will only attempt such if you are not happy with the integration between mid-dome and woofer after you have all else close to optimum ...
... for which yet we need new measured Frequency response and Impedance plots for both your mismatched HF2000s .
__________________
Alan

Last edited by alan-1-b; 3rd December 2013 at 03:15 PM. Reason: to tidy up some of the layout
  Reply With Quote
Old 5th December 2013, 11:05 AM   #1023
reggie is offline reggie  Australia
diyAudio Member
 
Join Date: Feb 2010
Location: melbourne australia
Hi Alan (et al).
Yes, very quick to complete the crossovers (2 months??). Plus 3 years of planning. Lessons learned: (i) do not use 12 gauge solid core wire in a crossover (almost impossible to get silver solder to adhere to it in a reasonable time (ii) don’t twist leads together and then solder them unless you intend to let them stay that way forever (iii) don’t try to reinvent the wheel – although only having one set of speaker wires from the amp to the crossover, I have three sets of wires (woofer, mid and tweeter + and -) from the crossover to the speakers.
Anyway. Despite my initial post expressing my joy at not having any teething problems several matters did come up that left me befuddled. The first was with a crackling sound coming from the right hand speaker followed by the woofer failing. It took a couple of days to find a bad solder joint. The second problem was quite strange. After soldering various resistors in and out of the circuit I was listening one night and the music wouldn’t centre itself. In fact the sound from the left speaker seemed to come from about 6 feet to the left of the speaker. That took a couple more days to discover one lead of the 8.2 ohm resister attached to the 4uf capacitor in the bass circuit had fractured, right up next to the resistor itself. Not having any more 8.2’s I soldered in two x 3.3ohm resistors in series. However, the focus then moved too much toward the right hand speaker so I wired in a 1.5ohm resister in parallel to the 8.2ohm resistor in the right hand crossover to bring it down a bit. My wife says the focus is pretty well centred now but I will order some more 8.2’s. To answer your question Alan yes, I am using the 70uF + 1 ohm Parallel with 4uF + 8.2 ohm and the 70uF + 1.5 ohm in the other location in that circuit. As for the tweeter Lpads I am using the 0.5ohm and 30.9ohm. I’ve found that, for most purposes, it provides me with more treble than before without becoming too obvious. For example in the Wishbone Ash tune “Warrior” to hear that cymbal passage we discussed in a previous post I had to put a cardboard tube to my ear and then put it up to the tweeter. Now, although still not hearing it from my listening position (12 feet from both speakers in a classic V format) if I move to within 4 feet I can hear it. So that’s a db increase to a factor of ????
The new bass capacitors I bought were Obbligato Film in Oil 70uf from DIYHiFi in Hong Kong. Unfortunately, I didn’t read the small print; these things are huge: 13 cms long and more in circumference. They take up a lot of space on the board. The boards I made with the speaker stands in mind so they measure 13” x 10”. Although I didn’t follow the inductor guidelines you specified in your last post I did look at a lot of pictures on the internet and read Troel Gravesen’s guidelines on inductor placement. I have mounted the big 3.45mh coil flat with the 2.2mh coil upright and at a 90 degree angle to it 7cm’s away. The other coils are oriented at 90 degree angles to each other and are spaced across the board.
Some early impressions. Over all, while I’m very happy with the bass (eg more punch with the kick drum and the whack of the snare (?) drum and more musical eg. more definition to something like a plucked bass) and the treble (leaving aside the loss of my high frequency hearing I am pleased with what I do hear with the Hiquphon. Very nice shimmer and decay to cymbal strikes etc. However, I’ve yet to try and fine tune the midrange. What I mean is that, as I understand it, the midrange is where all the voice action occurs so on some songs on some CDs some of the words/lyrics are indistinct. Now that could be because they are badly recorded However, I’ve noticed that with the new crossover I can discern/interpret more of these badly recorded passages than with the old crossover. I’m not sure whether to attribute that to (a) the lack of vibration from an externally mounted crossover (b) higher quality parts (c) changes made by the different architecture you’ve suggested in the crossover frequencies or (d) imagination on my part. Anyway, perhaps Alan you can tell me whether changing the resistor attached to the 4uf cap in the midrange could have an effect on clarity (I’m currently using the 3.9uf)?
I have taken some photographs and will post these when I learn how.
Well, enough for now. Thank you for reading.
Regards
Reggie
  Reply With Quote
Old 5th December 2013, 01:24 PM   #1024
diyAudio Member
 
LucasAdamson's Avatar
 
Join Date: Feb 2009
The real lesson I learned about silver solder is, don't use it at all! The presumption that the presence of silver in it will increase conductivity is erroneous. What you want is Lead! More specifically tin, lead and copper. Alan will no doubt back me up on this. It has made soldering a joy again, and my joints stronger physically and electrically.

I'm a Ditton 44 man, so shan't comment on the other stuff, other than to say well done!
__________________
Lucas
  Reply With Quote
Old 7th December 2013, 03:41 AM   #1025
DennyG is offline DennyG  Australia
diyAudio Member
 
Join Date: Feb 2010
Location: Sydney
Default Question for reggie re sound evaluations

What equipment are you using for your sound evaluations? And the room, is it small/large, damped/live?
  Reply With Quote
Old 16th December 2013, 10:05 PM   #1026
reggie is offline reggie  Australia
diyAudio Member
 
Join Date: Feb 2010
Location: melbourne australia
Hello Lucas. Yes, I remember now learning a lesson some time ago when I first used lead free soldier. Obviously I forgot what that lesson was. The solder I’m using now is a Mundorf silver/gold. The label tells me its lead and cadmium free and the contents are: S-sn95,5Cu0,7Ag3,8Au. With a 40w iron it melts very quickly on the inductor and capacitor leads (leaving a very neat shiny ball of solder) but using it to attach leads to the 12 guage wire was something else.
Hello DennyG.
Well my equipment for the last 4 years has been Elson Silva (Sydney based – you can read the review on his latest stuff here www.6moons.com/audioreviews/cymer/1.html ) monoblock push/pull valve amps operating in triode; a (second-hand) Cec TL1 Cd transport; an Audio Gd Mk7 dac; a Tram Mk 2 OTL pre-amp and of course the Celestions. The room is our 5.3m x 4.3m formal lounge-room so has a large stuffed couch (upon which I sit to listen) against the long wall facing the equipment, flanked by 2 stuffed chairs and a 2m x 3m Persian rug in the middle. It has shutters on the large front windows and glass framed artworks on every wall. The room and furniture are a constant. The room is not treated.
I don’t really analyse the sound I hear. There’s no AB as such. I play certain Cd’s more than others and have become familiar with them and, of course, I know the Celestions intimately having had them for 36 years. From my point of view there have been two sorts of changes; revolutionary and evolutionary. The two really big fundamental changes in my system have been the Cec which was a huge advance (from the Rega Apollo CD) in everything and the Audio Gd was a huge advance in depth and weight. Other changes have been more incremental. The Tram replaced a Bent Audio passive pre-amp (TAP). Initially there was only a very minor difference between them relating mainly to the “feel” of the music. Later with the addition of the Coleman heater modules for the 45/2A3 valves there was an improvement in clarity from the Tram. Then, at Alan’s suggestion the addition of the resistors and a change from the 34uf to a 24uf capacitor in the midrange of the Celestions wrought another small improvement. (I really cannot give you a better word than improvement. It means I’m hearing a more “alive” “realistic” “clearer “enjoyable” rendition of the music). Some changes I readily admit I cannot hear. I have spent a small fortune on NOS valves that make no apparent difference. Cables, interconnects etc. I have listened to for hours and cannot hear a difference. They might be there but with my ears and on my equipment I cannot hear it. So, with Alan’s crossover I am hearing an incremental change for the good.
I have no idea what my equipment sounds like vis a vis anybody elses (and maybe that’s a really good thing). I feel very happy about how it sounds…but I guess I still strive for that extra bit of realism (which is obtainable with some very fine recordings). Anyway. I’m going to experiment with different resistors in the midrange to see if one is “better” for me than another.
Regards
Reggie
  Reply With Quote
Old 20th December 2013, 06:00 AM   #1027
DennyG is offline DennyG  Australia
diyAudio Member
 
Join Date: Feb 2010
Location: Sydney
Default Reply to reggie

Hello reggie,
Thanks for the description. I'm not familiar with any of the components but I don't follow the hi-fi component area until I need to replace something. I agree with you about the importance of CD source components. I remember when I was upgrading my first CD player (a Nakamichi) Meridian had an integrated player and a separate transport & converter and both sounded good but when I borrowed both and listened on my system there was no comparison so I ended up buying the separates and still use them. For the 66s I use a fairly old BX model Rotel integrated player so that is an area I could probably improve on.

I described earlier the 66 sound improvements I heard when adding the resistors and then the next sound improvement with the new caps. I would describe them as revolutionary especially the resistors. The improvement with the caps was more subtle.

I also found significant differences in the resulting sound for various CD/amp interconnects. But I only have one really good interconnect set so that may be the reason. I've had most of my gear for many years. Amps are another component that needs further investigation.

I hope to get back to testing the drivers again and then adjusting the resistors for further improvements.

Good luck and hope you survived the recent Melbourne heat.

Regards
DG
  Reply With Quote
Old 20th December 2013, 04:17 PM   #1028
diyAudio Member
 
Join Date: Apr 2006
Location: Midlands
Default Layout of Posts for ease of reading and following , so as to be able to reply well

G'day Reggie ,

please refer to this Link here in diyaudio:

Opinions on tweeters please.

The above should take you to Page 8 of the Thread titled:
Opinions on tweeters please
which was stated by:
RDV

There I refer you to my Post #74.
Do not necessarily read that post , but look at how the Lay-Out is , and also in my 75 <--> 77 ,
and then please read the Moderator's reply and request in #78 , and my follow-up in #79 ,
and then his instructions to me in #80.
Next you can see my improvement in #87 on Page 9 of that Thread.

I list the above here , because I want you to know that I had very little Computer skills ,
{ and I still have only a few more now }.
It is thus not my intention to be rude , and I hope to not offend you by what I am going to ask ,
however I cannot easily follow your Posts.

My memory is not good for new information , thus to Reply to your Posts I have to re-read them during my replying to find the next bit of information ,
and that is very hard to find because so much is all on long lines and with very little spacing , even when you change Subject some-what.

I can see that you are aware of the function of the ENTER key , because sometimes you do start a new line , but not often enough.

I do NOT know what type of Computer you usually use ,
thus your Posts may look quite neat to you when you type them ,
however on the computers I have access to the way the Posts are changed causes very long lines with new Sentences starting mid-line and continuing into the next line.

I am sorry , but it is taking me too long to follow your information to be able to Reply in the limited amount of time I have available ,
thus I ask you , PLEASE set out your Posts with:
(1)- Each new Sentance starting on a new line ,
(2)- When you change Subject , even a little , please leave a Blank line , and start a new Paragraph.

The above is what I do in my Posts in the hope that interested readers are able to follow what I am stating.

I will now Copy your last Post to me , and Paste it in a new post below here ,
and I will space it in a way I can find the information in readily , so that you have an example of what I mean.
I will then Reply to it.

I apologize if the above may seem offensive to you , as I do not intend any offense.
I am simply trying to maximize efficiency.
__________________
Alan

Last edited by alan-1-b; 20th December 2013 at 04:25 PM. Reason: to correct an mistake in Post #s
  Reply With Quote
Old 20th December 2013, 06:02 PM   #1029
diyAudio Member
 
Join Date: Apr 2006
Location: Midlands
Default Initial Reply to #1023 - report of results by Reggie ; Agreement with LucasAdamson

Here is a Copy and Paste , and a re-setting of the spacings of #1023 :

Hi Alan (et al).

Yes, very quick to complete the crossovers (2 months??).
Plus 3 years of planning.
Lessons learned:
(i) do not use 12 gauge solid core wire in a crossover (almost impossible to get silver solder to adhere to it in a reasonable time
(ii) don’t twist leads together and then solder them unless you intend to let them stay that way forever
(iii) don’t try to reinvent the wheel – although only having one set of speaker wires from the amp to the crossover, I have three sets of wires (woofer, mid and tweeter + and -) from the crossover to the speakers.

Anyway. Despite my initial post expressing my joy at not having any teething problems several matters did come up that left me befuddled.
The first was with a crackling sound coming from the right hand speaker followed by the woofer failing.
It took a couple of days to find a bad solder joint.

The second problem was quite strange. After soldering various resistors in and out of the circuit I was listening one night and the music wouldn’t centre itself.
In fact the sound from the left speaker seemed to come from about 6 feet to the left of the speaker.
That took a couple more days to discover one lead of the 8.2 ohm resister attached to the 4uf capacitor in the bass circuit had fractured, right up next to the resistor itself.
Not having any more 8.2’s I soldered in two x 3.3ohm resistors in series. However, the focus then moved too much toward the right hand speaker so I wired in a 1.5ohm resister in parallel to the 8.2ohm resistor in the right hand crossover to bring it down a bit.
My wife says the focus is pretty well centred now but I will order some more 8.2’s.

To answer your question Alan yes, I am using the 70uF + 1 ohm Parallel with 4uF + 8.2 ohm and the 70uF + 1.5 ohm in the other location in that circuit.

As for the tweeter Lpads I am using the 0.5ohm and 30.9ohm.
I’ve found that, for most purposes, it provides me with more treble than before without becoming too obvious.
For example in the Wishbone Ash tune “Warrior” to hear that cymbal passage we discussed in a previous post I had to put a cardboard tube to my ear and then put it up to the tweeter.
Now, although still not hearing it from my listening position (12 feet from both speakers in a classic V format) if I move to within 4 feet I can hear it.
So that’s a db increase to a factor of ????

The new bass capacitors I bought were Obbligato Film in Oil 70uf from DIYHiFi in Hong Kong.
Unfortunately, I didn’t read the small print; these things are huge: 13 cms long and more in circumference.
They take up a lot of space on the board. The boards I made with the speaker stands in mind so they measure 13” x 10”.
Although I didn’t follow the inductor guidelines you specified in your last post I did look at a lot of pictures on the internet and read Troel Gravesen’s guidelines on inductor placement.
I have mounted the big 3.45mh coil flat with the 2.2mh coil upright and at a 90 degree angle to it 7cm’s away.
The other coils are oriented at 90 degree angles to each other and are spaced across the board.

Some early impressions.
Over all, while I’m very happy with the bass (eg more punch with the kick drum and the whack of the snare (?) drum
and more musical eg. more definition to something like a plucked bass) and the treble (leaving aside the loss of my high frequency hearing I am pleased with what I do hear with the Hiquphon.
Very nice shimmer and decay to cymbal strikes etc.

However, I’ve yet to try and fine tune the midrange.
What I mean is that, as I understand it, the midrange is where all the voice action occurs so on some songs on some CDs some of the words/lyrics are indistinct.
Now that could be because they are badly recorded However, I’ve noticed that with the new crossover I can discern/interpret more of these badly recorded passages than with the old crossover.
I’m not sure whether to attribute that to
(a) the lack of vibration from an externally mounted crossover
(b) higher quality parts
(c) changes made by the different architecture you’ve suggested in the crossover frequencies
or (d) imagination on my part.

Anyway, perhaps Alan you can tell me whether changing the resistor attached to the 4uf cap in the midrange could have an effect on clarity (I’m currently using the 3.9uf)?

I have taken some photographs and will post these when I learn how.

Well, enough for now. Thank you for reading.
Regards
Reggie

*** *** ***

Reggie ,
I don't know how the above re-sets itself for the screen width you have access to ,
but here's hoping ... !

My Replies:

(1)- 12 guage , you stated ...
Those inductors for the woofer section are 14 guage ,
and if you found AWG14 thickness a problem to work with ,
well ... wait till you have to work with AWG12 , if ever !

Basically what is happening is that thick wire is acting as a Heat Sink
and is drawing too much of the Iron's heat away from the point where the solder needs to adhere.
I hope you are soldering as follows:
Place the Tip of the hot iron onto the point on the wires' connection where you want to solder.
Hold it there till the wires' junction is hot.
Keep it there.
With your other hand , touch the end of the solder wire to the hot point of the component leads' junction ,
and hold it there till it melts.
After the melted solder has spread itself , remove the Iron ,
BUT hold firmly the components' leads in place until the solder sets.
If the leads move before the solder has fully set , the joint will be electrically poor ...
{ regardless of Silver and Gold in the solder , etc ... }
If you are close enough to the leads , blow on them - that will cool the solder to faster set ,
so that you are not struggling to hold the leads stable.
If the leads do move , then hold it down , apply the Iron and melt the solder at the junction ,
remove the Iron and hold firmly till the solder sets.
Sorry , it is tedious , but it will not work well otherwise ,
and will render irrelevant the benefits of expensive capacitors , etc ...
Basically , the wire needs to be hot enough for the solder to melt on the wire ,
and not only melt on the tip of the iron.

(2)- the less twisting together of leads the better for solder joints.
Do a short twist only ,
and better is to form a small hook shape at the end of each lead to hold them together and pressure the hooks together tightly with pliers ,
then solder over that hooks' junction.

(3)- Regardless of whatever instructions may have come with the Inductors ,
or that you may have read elsewhere ,
to solder Inductors into circuit with any DIY soldering iron , first scrape the insulating varnish off the ends of the Inductor ends' leads.
Use a sharp blade , or close pliers around the end of the wire and twist to remove a short length of the varnish completely.
Do not expect the hot iron to sufficiently remove the varnish.
That varnish is able to withstand heat - it has to ,
because it is used inside Transformers , etc , where the wire can get very hot !

(4)- The degree of Image Shift you described is result of more than simply one 4uF cap out of circuit with respect to 70uF.
It would require at least about twice that amount of capacitance difference to cause such shift , 10% , and likely require more.

If I have understood you correctly you have 1.5 ohm in Parallel with 8.2 ohm in one channel , and 6.6 ohms in the other ?
That would be 1.5//8.2 = about 1.33 ohm in one channel , and 6.6 ohms in the other.
Again , such amount of resistances in connection with only about 5.7% Nominal of the Total Capacitance would not alone cause such degree of Image Shift ,
and basically you have now set a new imbalance to attempt to correct a different cause of imbalance.
I think there is another problem , and which your remedies are assisting only part of.

Try this:
Remove both 4uF caps and their resistors from both channels of the crossover.
That is , have the 70uF caps and their resistors in circuit only.
Whilst you are doing that , look very carefully around the circuit to see if there are any places where there are Short Circuit and/or Open Circuit connections ...
... including solder joints that set whilst the leads were moving.

Next , listen with only the 70uF caps and their resistors in , with the 4uF caps and their resistors out.
Report the results here.

There is another possible cause of this Image Shift , unrelatated to the caps ,
but to diagnose that I will need to see Plan View photos of BOTH crossovers
so that I can see the exact Lay-Out on each board.
Even if both boards look close to identical lay-out to you , they may not be electrically.
I will explain how that can be after I see the photos ,
because then I can direct you where to look for problems.

(5)- Leave the Tweeter L-Pads as you had them , and also the Midrange resistors ,
until we sort out this Image Shift problem.

(6)- I posted what I thought about those Obbligato caps at point (7) in #902 on Page 91 ,
including their physical size.
OK , you have been determined to try them , and now you have ...
... that is your decision to make , and this is DIY ,
however if you had informed me you did not want to take the old Solens off the Celestion board I would have advised something else for new woofer filter caps , and smaller in physical size.

(7)- Are the 4uF caps in the Woofer filter Obbligato also ? ,
or what brand and type number ?

*** *** ***


I agree with LucasAdamson about not using Silver solder.

Silver solder is designed for use with components that have silver contact areas , and to connect silver or silver plated wire to those points.
The issue is to do with the integrity of the connection.
It is not anything to do with the small degree of silver's conductivity in the solder - so small there as to be irrelevant.

I advise use of 63/37 Tin/Lead solder , and that is Eutectic.
If you cannot obtain 63/37 , then use at least 60/40 Tin/Lead , and which is almost Eutectic.
It is worth the effort to find 63/37 , even if have to pay for Mail Order shipping ,
and relevant to what you have spent on crossover components Reggie , the cost of decent solder is a minor point !

Ideally , I would remove all the Silver solder from the crossovers and re-do with 63/37 ,
however leave it for now Reggie , because there is more disconnecting you may need to do yet to solve this Image Shift problem.

Do NOT mix the existing Silver/Gold solder with any new bought 63/37 at the same joint points.

I have not researched this Mundorf Silver/Gold solder to find whatever claims about it ,
however Cardas did have some useful information about their different formulations of solders.

I posted about Solder earlier in this Thread , or perhaps it was only in another Thread I posted it ... ?


G'day DennyG ,

Do you remember if I posted about types of Solder here ?
I think it may have been in discussion with you and Wayne Swann I posted about the solder types , over a year ago ...
What solder type do you use ?
__________________
Alan

Last edited by alan-1-b; 20th December 2013 at 06:19 PM. Reason: to add a sentance , and change a few words
  Reply With Quote
Old 21st December 2013, 05:14 AM   #1030
DennyG is offline DennyG  Australia
diyAudio Member
 
Join Date: Feb 2010
Location: Sydney
Default Solder

Alan, your Post # 592 had information on solder.

I use 60/40 of various thicknesses.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 03:51 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2